Normally the radio model is used for monitoring or controlling the switching device. A person who is equipped with a suitable receiving device can retrieve the available information without having to come into direct contact with the control apparatus. A complex structure of a wired bus system can be omitted. Moreover, in an emergency an appropriate message can be transmitted automatically to the receiving device using the radio module and the competent person can therefore be reached irrespective of where they are.
A switching apparatus of this kind is described in DE 10 2004 002 330 A1. The switching device of the switching apparatus is arranged in a control cabinet. A radio interface is connected to the switching device and is provided for the purpose of exchanging information regarding the operating state of the switching device with an appropriate radio interface of the receiving device.
In particular, the switching apparatus disclosed in DE 10 2004 002 330 A1 is permanently able to communicate. This is, however, associated with disadvantages. The radio module that is permanently able to communicate can be manipulated by unauthorised access. For example, data stored in the radio module could be read wrongfully. Moreover, the communication between the radio module and the receiving device could be followed. Critical malfunctions of the switching apparatus could be brought about by access to the data transmission or the radio module respectively. The security of the switching apparatus and in some circumstances a whole system connected to the switching apparatus is thus compromised.